/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.optimize.peephole;

import proguard.classfile.*;
import proguard.classfile.util.*;
import proguard.classfile.visitor.MemberVisitor;
import proguard.optimize.KeepMarker;

/**
 * This <code>MemberVisitor</code> makes the program methods that it visits final, if possible.
 *
 * @author Eric Lafortune
 */
public class MethodFinalizer extends SimplifiedVisitor implements MemberVisitor {
    private final MemberVisitor extraMemberVisitor;

    private final MemberFinder memberFinder = new MemberFinder();

    /**
     * Creates a new ClassFinalizer.
     */
    public MethodFinalizer() {
        this(null);
    }

    /**
     * Creates a new ClassFinalizer.
     * 
     * @param extraMemberVisitor an optional extra visitor for all finalized methods.
     */
    public MethodFinalizer(MemberVisitor extraMemberVisitor) {
        this.extraMemberVisitor = extraMemberVisitor;
    }

    // Implementations for MemberVisitor.

    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) {
        String name = programMethod.getName(programClass);

        // If the method is not already private/static/final/abstract,
        // and it is not a constructor,
        // and its class is final,
        // or it is not being kept and it is not overridden,
        // then make it final.
        if ((programMethod.u2accessFlags & (ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC
            | ClassConstants.ACC_FINAL | ClassConstants.ACC_ABSTRACT)) == 0
            && !name.equals(ClassConstants.METHOD_NAME_INIT)
            && ((programClass.u2accessFlags & ClassConstants.ACC_FINAL) != 0 || (!KeepMarker.isKept(programMethod)
                && (programClass.subClasses == null || !memberFinder.isOverriden(programClass, programMethod))))) {
            programMethod.u2accessFlags |= ClassConstants.ACC_FINAL;

            // Visit the method, if required.
            if (extraMemberVisitor != null) {
                extraMemberVisitor.visitProgramMethod(programClass, programMethod);
            }
        }
    }
}